Mastication muscles Flashcards
Lateral pterygoid
supeprficial head
O
I
O: greater wing of spenoid (infratemporal) lateral surface
I: articular disc and capsule of TMJ
Lateral pterygoid
Inferior head
O
I
O: Lateral pterygoid plate lateral surface
I: Ramus (lateral), condylar neck (process)
Lateral pterygoid action
Protrude (pulls articular disc forward)
Depresses
Excursion
Lat pterygoid assoc structures
Maxillary artery runs superficial or deep
Pterygoid venous plexus
CN 5 buccal branch runs btw the 2 heads
Medial pterygoid
Superficial head
O
I
O: Maxillary tuberosity
I: Medial surface of ramus and angle
Medial pterygoid
Deep head
O
I
O: Lateral pterygoid, medial surf
Medial pterygoid plate, lateral surface
Pterygoid fossa
I: Medial surface of ramus and angle
Medial pterygoid action
Elevates
Protrudes
Excursion
Medial Pterygoid assoc structures and special note
- Deepest muscle of mastication
- Can penetrate during mandibular block if needle is placed below the mandibular foramen
- Contacts
- Parotid Gland
- Inferior alveolar ARTERY
- Inferior alveolar NERVE
- Lingual NERVE
- Chorda tympani N
Masseter
Superficial Head
O
I
Size and fibers
- Larger, fibers run down and back
- O: Anterior 2/3 zygomatic
- I: Lateral surface of ramus
Masseter
Deep head
O
I
Size and fibers
- Smaller, fibers run vertical
- O: Post 2/3 zygomatic
- I: :ateral of ramus and coronoid
Masseter action
Elevate (Clenching)
Superficial head protrudes
Excursion
Masseter assoc structures
Superficial to masseter
Parotid gland
Tranverse facial artery
Branches of CN 7
Temporalis
O
I
- O: Temporal fossa, inferior temporal line, fascia
- I: Travels under zygomatic arch
- Coronoid process
- Anterior border of ramus
Temporalis Action
- Anterior vertical fibers
- Elevate
- Middle/oblique and posterior horizontal
- Retract mandible
- Keeps jaw in resting position
